2012-07-10 09:44:17 -04:00
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subroutine analytic(d,npts,nfft,s,c)
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! Convert real data to analytic signal
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2012-07-17 15:31:01 -04:00
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parameter (NFFTMAX=128*1024)
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2012-07-10 09:44:17 -04:00
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real d(npts)
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real s(npts)
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2012-07-17 15:31:01 -04:00
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complex c(NFFTMAX)
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2012-07-10 09:44:17 -04:00
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nh=nfft/2
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fac=2.0/nfft
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c(1:npts)=fac*d(1:npts)
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c(npts+1:nfft)=0.
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call four2a(c,nfft,1,-1,1) !Forward c2c FFT
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do i=1,nh
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s(i)=real(c(i))**2 + aimag(c(i))**2
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enddo
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c(1)=0.5*c(1)
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c(nh+2:nfft)=0.
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call four2a(c,nfft,1,1,1) !Inverse c2c FFT
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return
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end subroutine analytic
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